CONCORD — It was late at night on Oct. 19, 1994, when Robert A. Ivarson stood on the back porch of his parents’ Lexington home, clad in a bullet-proof vest, and fired a single shot into the Sutherland Woods.

Police responded quickly and Ivarson’s parents were petrified, telling police Ivarson was mentally ill and likened himself to Claude Dallas, a poacher who shot and killed two fish and game officers in Idaho in 1981, according to court records.

Ivarson, then 27, had told his parents that if they called the police he would kill the officers, court records stated.

Police seized his weapons and revoked his firearms licenses. He was sentenced to two years of probation and ordered to receive counseling.

But a year later, Ivarson was arrested again after aiming an empty pistol at his father’s head, records show. Police confiscated a rifle, a handgun, and more than 2,500 rounds of ammunition from a locker in his room. He was sentenced to 2½ years in prison.

On Monday, more than two decades later, Ivarson, 49, was arraigned in Concord District Court on strikingly similar charges, after Lexington police discovered more than 80 firearms and about 100,000 rounds of ammunition in his parents’ home.

Ivarson pleaded not guilty to an array of gun and ammunition charges, and was ordered held without bail until a Jan. 17 hearing to determine whether he poses a risk to public safety.

The gun charges follow Ivarson’s arrest on harassment and civil rights violations after he allegedly threw dozens of banana peels onto the property of a black family in his neighborhood. Prosecutors said the vandalism was racially motivated.

In a search of Ivarson’s parents’ Tarbell Avenue home, investigators found gun cabinets, safes, and boxes of ammunition in his bedroom, according to a police report. They also seized a World War II German-style helmet with a Nazi insignia and 50 pounds of black powder.

Ivarson’s parents are cooperating with investigators and police do not believe they were aware of the weapons, said Middlesex District Attorney Marian T. Ryan.

The weapons were stored in a part of the home only Ivarson could access, she said.

Prosecutors would not comment on how Ivarson was able to purchase such a large number of firearms without a license, saying it was part of the investigation.

Lexington police are still cataloging the items, prosecutors said.

The neighbor Ivarson allegedly targeted, Frantz St Fort, said the harassment started 18 months ago, but he initially didn’t think anything of it.

“I didn’t know it was something serious,’’ St Fort said from the doorway of his home, just a few doors down from Ivarson’s. “My wife said we had to do something.’’

St Fort, 41, said he and his family moved into the home nine years ago from Haiti.

He said he had been to Ivarson’s home once, and that Ivarson had allowed him to dump leaves by his house.

Now, St Fort said his 11-year-old daughter is scared.

“He was very friendly to me,’’ St Fort said. “I don’t know why he did this.’’

Ivarson’s court-appointed lawyer, Stephen McClenon, declined to discuss his client’s case.

According to court documents, Ivarson had told a police officer that his neighbors across the street were “a black family that he claimed was ‘Section 8’ and that they had nice cars for Section 8 people.’’ Section 8 refers to the federal government’s housing voucher program for low-income families.

In 1995, police urged Ivarson’s parents to take out a restraining order against him, but they refused, court records show. After he pulled a gun on his father, he injured his wrist and back in a tussle, destroyed household items, and “trapped’’ his parents in their home during a 30-minute tirade, records show.

Ivarson’s mother, Maribeth, told police that officers “were incapable of protecting them, the courts are a joke, and the prisons do nothing but make hardened criminals.’’

She told police her son had repeatedly threatened to kill them after the 1994 incident and had abused her husband. She said Ivarson, a former truck driver, had a drinking problem and was once committed to the Arborway Mental Health facility in Jamaica Plain for 60 days. He had refused to get any help since, she said.

After he was fired from his job in 1994, he tried to run over a police officer with his truck, records show. At the time, his parents told police he had also worked in firearms sales and that he had a safe “as big as a refrigerator’’ filled with weapons.

Jan Ransom can be reached at jan.ransom@globe.com. Follow her on Twitter at @Jan_Ransom.